topic Re: Vector Tiles Many Duplicate Labels at High Zoom in ArcGIS Enterprise Portal Questions

Vector Tiles Many Duplicate Labels at High Zoom

JCGuarneri — Wed, 30 Aug 2023 17:19:42 GMT

I have a long-standing issue with my vector tiles that I've been trying to resolve. The issue is that I design my label classes in Pro and get results that I like. However, in the published vector tiles, there are invariably high densities of repeating labels at high zoom levels (see examples below). I've gone through the suggestions in https://pro.arcgis.com/en/pro-app/latest/help/mapping/map-authoring/labeling-in-vector-tiles.htm and made adjustments accordingly, but I still see this issue. I suspect there's something simple I'm missing. Does anyone have a good suggestion?

I'm working in Enterprise 10.9.1, publishing from Pro 3.1.3, but this has been an issue for years.

Desired:

Actual:

Re: Vector Tiles Many Duplicate Labels at High Zoom

Bilal_Alam_GIS — Tue, 26 Sep 2023 12:40:37 GMT

Could you please try Enable scale-based sizing and remove duplicate labels in label setting:

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChelseaRozek — Mon, 24 Feb 2025 19:50:27 GMT

Those suggestions did not fix it for me.

@JCGuarneri , did you find any work arounds?

Re: Vector Tiles Many Duplicate Labels at High Zoom

JCGuarneri — Mon, 24 Feb 2025 20:15:00 GMT

@ChelseaRozek It turns out this is caused by Vector Tiles using the default labeling engine and not Maplex. So the "fix" is to use Annotations for various zoom levels, if you have time for that. I learned that from some members of the Esri Maplex team that were kind enough to take an interest in my map gallery entry at UC.
Completely forgot about this post, otherwise would have updated earlier!

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChelseaRozek — Mon, 24 Feb 2025 21:07:35 GMT

@JCGuarneri Thanks for the quick reply! That's a bummer, feels like a step backwards instead of forward... May have to stop using them.

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChrisWesson — Mon, 07 Apr 2025 23:51:25 GMT

@JCGuarneri If I understand your question correctly then the workaround is not annotations, they are not currently compatible with vector tiles. Remove duplicates will also be ignored.

If your roads are lines, then you can use the option under Repeat > Minimum interval. I know in GIS you would often use this to increase the frequency of labels but when creating vector tiles it is also useful for limiting the frequency of labels. The reason being is that this setting gets converted to the vector tile "symbol-spacing" property. For the river polygon, if you use the Maplex placement "Curved in polygon" then you can also use the Repeat > Minimum interval setting in the same way.

Re: Vector Tiles Many Duplicate Labels at High Zoom

JCGuarneri — Tue, 08 Apr 2025 11:38:41 GMT

@ChrisWesson I'm already using Minimum Interval, and it doesn't seem to be honored by the vector tiles. Enterprise 11.1, published from Pro 3.2.3. Are there any special tricks or constraints to be aware of to make sure it works properly?

As for the Annotations, perhaps I misunderstood the folks I talked to at UC. I haven't actually tried annotations to confirm or deny.

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChelseaRozek — Tue, 08 Apr 2025 13:29:24 GMT

@ChrisWesson I bumped up the Minimum Interval and republished to ArcGIS Online but I'm still getting the duplicate road labels as seen in my screenshot earlier in this thread.

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChrisWesson — Tue, 08 Apr 2025 15:29:02 GMT

Sorry to hear this @ChelseaRozek . I sometimes get the same.
Other things you could try are joining segmented road sections or editing the JSON to include the Mapbox setting "text-repeat-distance".
Beyond that, what you are likely seeing is repeats across different tiles. My understanding is that the rules beyond a tile edge only extend within a small buffer distance. The only way around this is to try to force less labels by modifying the tile index. Essentially it would be the opposite of this workflow. So try for example increasing the maximum vertex count to 50,000. But that may reduce performance.

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChrisWesson — Fri, 11 Apr 2025 23:23:54 GMT

@JCGuarneri I presume they meant converting feature labels or annotations to labelled point features.

Anyway, tricks listed above 🙂

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChelseaRozek — Tue, 08 Apr 2025 18:15:27 GMT

I tried dissolving my roads based on name and a few other fields we use to label. I tried adding in "text-repeat-distance" in the Vector Tile Style Editor's JSON editing (after confirming I was on the right label class by changing the text color). Neither helped. I wouldn't think it's a tile issue as I'm only looking at an 800 ft driveway.

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChrisWesson — Fri, 11 Apr 2025 21:59:38 GMT

@ChelseaRozek @JCGuarneri Sorry none of this helped. We are fully aware that the labelling options in vector tiles are currently limited when compared to Maplex.
It is possible that what you are seeing is related to a bug we are currently investigating. It is also possible that small undissolved road segments and divided highways could be the cuplrit if you want to check for those.

Unfortunately I don't think there's anything else we can try.

Re: Vector Tiles Many Duplicate Labels at High Zoom

JordanCarmona — Tue, 16 Sep 2025 17:47:27 GMT

Is this still unresolved? I see that it is in the product plan, are we talking 3.7? or is that a more aspirational in the product plan?

This is the same as the bug(s) from 2018?

https://support.esri.com/en-us/bug/vector-tiles-are-repeating-labels-in-linear-features-in-bug-000116520

https://support.esri.com/en-us/bug/duplicate-labels-appear-in-the-vector-tile-package-outp-bug-000115211

BUG-000130533 (unable to find URL)

Also referenced here:

https://community.esri.com/t5/arcgis-pro-questions/duplicate-labels-show-when-exporting-to-agol/td-p/1050622

https://community.esri.com/t5/arcgis-online-ideas/fix-labeling-limitations-for-vector-tiles/idi-p/953232

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChrisWesson — Tue, 16 Sep 2025 22:55:14 GMT

@JordanCarmona @JCGuarneri @ChelseaRozek

I'd love to help finally get to the bottom of this. For us to better assist with unexpected repeating labels, can you please provide any sample data as a support case? It is hard to see what is going on without examing the tiles and changes between levels of detail.

I looked into the 2018 issue for clarification. The customer bug is that remove duplicates does not work, this is expected behavior. The reason we have an issue open is because while remove duplicates should not work, it does seem to be working with horizontal placements in current releases.

Fix labelling limitations is a far, far broader topic for discussion. At present vector tile specification simply does not allow us to control labelling in a similar way to Maplex.

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChelseaRozek — Wed, 17 Sep 2025 20:06:43 GMT

Hi @ChrisWesson, you can view it just south of this parcel in our public app. I can open a support case to send a vtpk over, but is there a way we can escalate it to your team from the get-go? Which product should we call it as it's across Pro/Enterprise/AGO?

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChrisWesson — Wed, 17 Sep 2025 22:57:56 GMT

If you can open a support case with VTPK that would make it much easier, thanks.
Report it for the attention of the ArcGIS Pro, Multiscale Mapping team. That should help it get to us.

Thank you!

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChelseaRozek — Tue, 23 Sep 2025 13:02:54 GMT

@JordanCarmona It's been logged as a bug now, BUG-000179651

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChrisWesson — Tue, 07 Oct 2025 19:00:06 GMT

I don't have the Nashua data but looking at the supplied data for Washtenaw County and Pierce County, in both of those datasets the repeat labels are almost all caused by tile edges.
We would like to improve this going forward with an enhancement but it is not that easy to address. I'll try to keep you posted but its not currently in a release pipeline.

For now I am closing the bug because unfortunately the repeat labels are expected since the roads are labelled once on each tile. Occasionally you may also see a repeat label within a tile close to the edge cause by the buffer, usually if labels cross the tile edge.

If you are happy for me to share, I can post screenshots showing a few extracts of the supplied data with the tile edges added. I attached them to the internal notes on the bug so it might be that the case contacts can also email them to you.
Note that you can do/check this yourselves by running the create vector tile index tool before creating your vector tile packages.

Chris

Re: Vector Tiles Many Duplicate Labels at High Zoom

JordanCarmona — Tue, 07 Oct 2025 19:39:58 GMT

Maybe this is a little bit of inside baseball; is there any discussion on a timeline (assuming the decision is a default yes) for adopting the maplibre tile specification?

https://github.com/maplibre/maplibre-tile-spec

https://github.com/mactrem/presentations/blob/main/FOSS4G_2024_Europe/FOSS4G_2024_Europe.pdf

https://www.youtube.com/watch?v=YHcoAFcsES0

https://www.arxiv.org/abs/2508.10791

And yes, please, anything that you wouldn't mind sharing would be helpful for us; and I'm sure others.

Re: Vector Tiles Many Duplicate Labels at High Zoom

ChrisWesson — Tue, 07 Oct 2025 19:55:52 GMT

I'm not privy to such discussions or timelines but we are aware of the Vector Tile evolution from MapLibre and others involved. Thanks